New Food Illness Tests Pose a Problem, CDC Warns

"Foodborne infections continue to be an important public health problem in the United States," said Dr. Robert Tauxe, M.D., MPH, director of CDC's Division of Foodborne, Waterborne and Environmental Diseases. "We are working with partners to make sure we still get important information about harmful bacteria despite the increasing use of diagnostic tests that don't require a culture."

Apr 18, 2016

CDC warned last week that changes in the tests used to diagnose foodborne illness are helping identify infections faster, but they may soon pose challenges to finding outbreaks and monitoring progress toward preventing foodborne disease. The report on this was published today in CDC's Morbidity and Mortality Week Report and discussed culture-independent diagnostic tests (CIDTs).

These tests help doctors because they provide results in hours instead of the days needed for traditional culture methods, which require growing bacteria to determine what has caused an illness. "But without a bacterial culture, public health officials cannot get the detailed information about the bacteria needed to help find outbreaks, check for antibiotic resistance, and track foodborne disease trends," according to CDC, which also reported that the percentage of foodborne infections diagnosed only by CIDTs in 2015 was about double compared with the percentage in 2012-2014.

"Foodborne infections continue to be an important public health problem in the United States," said Dr. Robert Tauxe, M.D., MPH, director of CDC's Division of Foodborne, Waterborne and Environmental Diseases. "We are working with partners to make sure we still get important information about harmful bacteria despite the increasing use of diagnostic tests that don't require a culture."

Because the rising used of CIDTs could affect public health officials' ability to monitor trends and detect outbreaks, for now, clinical laboratories should work with their public health laboratories to make sure a culture is done whenever a CIDT indicates someone with diarrheal illness has a bacterial infection, according to CDC, which says it is working with partners on a long-term solution to develop advanced testing methods that, without culture, will give health care providers information to diagnose illness and also give the detailed information that public health officials need to detect and investigate outbreaks.

The report included the most recent data from CDC's Foodborne Diseases Active Surveillance Network. Overall, little progress has been made since 2012 in reducing rates of foodborne illnesses; the most frequent causes of infection in 2015 were Salmonella and Campylobacter, consistent with previous years.